Freescale Semiconductor MPC8260 - Manual (Page 1162)

Inverse Multiplexing for ATM (IMA)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
33-60 Freescale Semiconductor
33.5.3.2 General Operation
• React to received ICP cells. ICP cells are only received when their SCCI field changes, except the
first received ICP cell
• Report any NE and FE timing mode mismatches (ITC vs. CTC) to the Unit Management
33.5.3.3 Receive Link State Machine Control
• Set up unassigned links, awaiting ICP cells
— Define either as standard multi-PHY or as unassigned IMA link
— Set up receive channel for ICP OAM cells for this link only
• Create and initialize delay compensation buffer
• Respond to received ICP cells. Extract and validate link/group parameters
— IMA ID
— Link ID
— Link ICP offset
— IMA frame size (M)
• After establishment of group, change receive channel for ICP OAM cells such that all links in the
group point to the same channel
• Control link operation (via ILRCTNL[RXSC]) in coordination with link and group states
33.5.3.4 Receive Group State Machine Control
• Coordinate receive links, using received ICP cells to identify a proposed group
• Establish and validate group parameters in conjunction with the received link states and parameters
— IMA version
— IMA ID
— Group order table
• Enable delay synchronization for the group, and react to its completion
• Control group operation (via IGRCNTL[RXSC]) in coordination with group state
• Signal receive group state via ICP cells of corresponding transmit group
33.5.3.5 Transmit Link State Machine Control
• Define the IMA link
— Define link parameters (e.g. IMA ID, Link ID, IMA frame size (M)) in coordination with IMA
group definition
— Assign ICP offset
— Create and initialize transmit queue
• Control link operation (via ILTCNTL[TXSC]) in coordination with link and group states